Patent Grant
12046824
The present invention relates to an antenna, specifically to an ultra-wideband cross-polarized antenna and ultra-wideband cross-polarized array antenna for millimeter wave or other frequency band applications.
The statements herein merely provide background information related to the present invention and do not necessarily constitute the prior art.
At present, most 5G millimeter wave array antennas use patch elements, which are convenient for feeding, but have narrow bandwidths, low isolations between two cross-polarized ports and narrow beam scanning ranges. To improve performances of patch antenna elements, complex structures such as multilayer PCBs stacking, aperture coupling, and multiple parasitic elements are often used.
In “A Planar Dual-Polarized Ultra-Wideband Millimeter Wave Array Antenna” (S. M. Moghaddam, J. Yang and A. A. Glazunov, Antennas and Propagation (EUCAP), 2018 12th European IEEE Conference), ultra-wide antennas for millimeter wave application have been studied in literature, where antenna elements consist of bowtie patches integrated with I′-shaped feed probes, and the array antenna consists of tightly-coupled bowties in a dual-offset configuration. The elements are fed by 50 Ohm Coaxial Cable and the array is fed by 75 Ohm Coaxial Cable below the ground plane.
In addition, other examples of broadband antennas with integrated feed networks are magnetoelectric dipoles. However, these antennas are mostly considered for single-antenna structures, operating in the 1.6-3.8 GHz frequency band, fed through an SMA connector below the ground plane, and unsuitable for 5G millimeter wave frequency bands.
There is provided an ultra-wideband cross-polarized antenna including a substrate, a first polarized antenna and a second polarized antenna. The substrate includes a first substrate layer and a ground layer stacked in sequence; the first polarized antenna and the second polarized antenna are provided in the first substrate layer, with first polarized antenna orthogonal to the second polarized antenna.
The first polarized antenna includes a first branch, a second branch, a first ground pin, a second ground pin and a first feed structure. The first branch and the second branch are located on the same plane; the first ground pin has one end connected to the first branch, and the other end connected to the ground layer; the second ground pin has one end connected to the second branch, and the other end connected to the ground layer; and the first feed structure is located between the first ground pin and the second ground pin for providing coupling for the first branch and the second branch.
The second polarized antenna includes a third branch, a fourth branch, a third ground pin, a fourth ground pin and a second feed structure. The third branch and the fourth branch are located on the same plane; the third ground pin has one end connected to the third branch, and the other end connected to the ground layer; the fourth ground pin has one end connected to the fourth branch, and the other end connected to the ground layer; and the second feed structure is located between the third ground pin and the fourth ground pin for providing coupling for the third branch and the fourth branch.
The ultra-wideband cross-polarized antenna has a simple structure, is able to solve challenging bandwidth issues, cross-polarized port isolation issues and beam scanning range issues in 5G millimeter wave array antennas and is easy to integrate with a beamformer RFIC on a main PCB board.
More illustrative information regarding various alternative architectures and uses by which the foregoing methods are achievable or unachievable will now be set forth according to user needs. It should be strongly noted that the following information is presented for illustrative purposes and should not be interpreted as limiting in any way. Any of the following features may optionally be combined with or does not exclude other features described.
Similar to a radio frequency integrated circuit (RFIC) chip, the antenna structure in the embodiment can be welded to a mainboard by providing feed ports and pads at its bottom, and is easy to integrate with a beamformer RFIC on a main PCB, therefore constructing different array antennas for 5G millimeter wave wireless communication device applications.
A structure and composition of the first polarized antenna will be firstly described below.
Specifically, the first feed structure includes a first feed section 205, a second feed section 206 and a third feed section 207 connected in sequence, and the second feed section 206 is parallel to the first branch 201 and the second branch 202 respectively and is vertical to the first feed section 205 and the third feed section 207 respectively, with the third feed section 207 having a smaller length than the first feed section 205. That is, the first feed structure is η-type, one end of the first feed section 205 away from the second feed section 206 is conductive with feed lines provided below the ground layer 120, and one end of the third feed section 207 away from the second feed section 206 is suspended.
Continuing as shown in
Continuing as shown in
In one embodiment, the first feed section 205 has the same length as the first ground pin 203 and the second ground pin 204, which is about ¼λ, where λ is a wavelength corresponding to a center frequency of a working frequency band.
In a single polarized antenna, two horizontally placed branches form a balanced electric dipole antenna, and two vertical ground pins and a η-type feed structure in the middle form a magnetic dipole antenna. That is, the single polarized antenna includes the magnetic dipole antenna placed vertically and the balanced electric dipole antenna placed horizontally.
In the η-type feed structure, the first feed section 205 and the third feed section 207 which are vertically oriented provide capacitive coupling, while the horizontally oriented second feed section 206 provides inductive coupling. Both the magnetic dipole antenna and the electric dipole antenna can be excited and tuned by adopting the above feed structure, so that an ultra-wideband antenna can be obtained.
The second polarized antenna 300 basically has the same structure and size as the first polarized antenna 200, and differs in the height of the feed structure from the first polarized antenna 200 to avoid the overlapping of the feed structures of the two polarized antennas. A structure and composition of the second polarized antenna will be described below.
Specifically, the second feed structure includes a fourth feed section 305, a fifth feed section 306 and a sixth feed section 307 connected in sequence, and the fifth feed section 306 is parallel to the third branch 301 and the fourth branch 302 respectively and is vertical to the fourth feed section 305 and the sixth feed section 307 respectively, with the sixth feed section 307 having a smaller length than the fourth feed section 305. That is, the second feed structure is η-type, one end of the fourth feed section 305 away from the fifth feed section 306 is conductive with feed lines provided below the ground layer 120, and one end of the sixth feed section 307 away from the fifth feed section 306 is suspended.
Continuing as shown in
Continuing as shown in
In an optional embodiment, the fourth feed section 305 may have a larger length than the first feed section 205, or may also have a smaller length than the first feed section 205, so that the second feed section 206 and the fifth feed section 306 are located on different planes so as to avoid the overlapping of the second feed section 206 and the fifth feed section 306, thereby avoiding the overlapping of the first feed structure of the first polarized antenna 200 and the second feed structure of the second polarized antenna 300.
In the embodiment, the fourth feed section 305 has a larger length than the first feed section 205 with the length difference of 100 μm.
In the embodiment, the first branch 201 and the second branch 202 have the same length direction as the second feed section 206, and the third branch 301 has the same length direction as the fourth branch 302, with the length direction of the first branch 201 and the second branch 202 vertical to that of the third branch 301 and the fourth branch 302. The second feed section 206, the first branch 201, the second branch 202, the third branch 301 and the fourth branch 302 are located on the same plane, and projections of the second feed section 206 and the fifth feed section 306 on the ground layer 120 are vertical to each other. The first stub tuner 208 and the second stub tuner 308 have the same length and are located on the same plane; and the first pad 209 and the second pad 309 have the same shape and size and are located on the same plane.
In some embodiments, the substrate may be composed of metal layers and dielectric layers of a multilayer PCB. In an optional embodiment, the first substrate layer may include four metal layers stacked in sequence, namely, a first metal layer, a second metal layer, a third metal layer, and a fourth metal layer in sequence from top to bottom, with the ground layer taken as a fifth metal layer; and the second substrate layer may include three metal layers stacked in sequence, namely, a sixth metal layer, a seventh metal layer and a eighth metal layer in sequence from top to bottom, with a dielectric layer provided between every two adjacent metal layers. That is, the substrate can be composed of eight metal layers and seven dielectric layers, with the metal layers and the dielectric layers alternately stacked. Strip-line structures are formed between the ground layer (the fifth metal layer), the sixth metal layer and the seventh metal layer.
Herein, the fifth feed section of the second polarized antenna is formed on the first metal layer; the first branch, the second branch and the second feed section of the first polarized antenna, and the third and fourth branches of the second polarized antenna are formed on the second metal layer; the first pad of the first polarized antenna and the second pad of the second polarized antenna are formed on the third metal layer; the first stub tuner of the first polarized antenna and the second stub tuner of the second polarized antenna are formed on the fourth metal layer; the first feed line of the first polarized antenna and the third feed line of the second polarized antenna are formed on the sixth metal layer; and the second feed line of the first polarized antenna and the fourth feed line of the second polarized antenna are formed on the eighth metal layer.
Moreover, the first ground pin, the second ground pin, the first feed section and the third feed section of the first polarized antenna, and the third ground pin, the fourth ground pin, the fourth feed section and the sixth feed section of the second polarized antenna, may be composed of vias (metallized holes) provided in the first substrate layer.
Similarly, the conduction between the first feed section, the first feed line and the second feed line, and the conduction between the fourth feed section, the third feed line and the fourth feed line, can also be realized by vias provided in the second substrate layer.
Specifically, in the embodiment, as shown in
One end of the first feed section 205 away from the second feed section 206 passes through the first through hole 121 and is connected to one end of the first feed line 210 through the first via 131, and the other end of the first feed line 210 is connected to one end of the second feed line 211 through the second via 132. One end of the fourth feed section 305 away from the fifth feed section 306 passes through the second through hole 122 and is connected to one end of the third feed line 310 through the third via 133, and the other end of the third feed line 310 is connected to one end of the fourth feed line 311 through the fourth via 134.
Herein, the first through hole 121 has a larger transverse cross-sectional area than the first feed section 205, and the second through hole 122 has a larger transverse cross-sectional area than the fourth feed section 305, so as to avoid the grounding of the feed structures.
In an optional embodiment, a plurality of metallized holes 135 are further provided in the second substrate layer 130 (specifically provided between the ground layer, the sixth metal layer and the seventh metal layer) and the metallized holes 135 are provided around the first feed line 210 and the third feed line 310 for shielding interferences between the feed lines. In an optional embodiment, the plurality of metallized holes 135 provided in the second substrate layer 130 are also provided around a single cross-polarized antenna, that is, the plurality of metallized holes 135 are distributed on edges of the second substrate layer 130 of the single cross-polarized antenna, so as to shield interferences between different cross-polarized antennas when a plurality of cross-polarized antennas are integrated into an array antenna.
For example,
In some embodiments, the ultra-wideband cross-polarized antenna further includes at least one support pad 400 provided on the side of the second substrate layer 130 away from the ground layer 120, namely, on the eighth metal layer. In the embodiment, as shown in
With the above structures, the ultra-wideband cross-polarized antenna can be welded on a top layer of the main PCB and be integrated with the beamformer RFIC, therefore constructing array antennas of different sizes for 5G millimeter wave wireless devices.
In an optional embodiment, the 4×4 ultra-wideband cross-polarized array antenna 3000 measures 27.4 mm by 27.4 mm by 2.39 mm, which, at this time, can cover a low frequency band of 5G millimeter wave applications. In another optional embodiment, the 4×4 ultra-wideband cross-polarized array antenna 3000 measures 20.4 mm by 20.4 mm by 1.59 mm, which, at this time, can cover a high frequency band of 5G millimeter wave applications.
In one embodiment, the ultra-wideband cross-polarized antenna measures 5 mm by 5 mm by 2.22 mm, which, in the embodiment, is used to cover the low frequency band (24.25-29.5 GHz) of 5G millimeter wave applications.
In one embodiment, a 1×4 ultra-wideband cross-polarized array antenna is formed by the above ultra-wideband cross-polarized antennas for covering the low frequency band of 5G millimeter wave applications.
In another embodiment, the ultra-wideband cross-polarized antenna measures 4 mm by 4 mm by 1.533 mm, which, in the embodiment, is used to cover the high frequency band (37-52.6 GHz) of 5G millimeter wave applications. The ultra-wideband cross-polarized antenna for covering the high frequency band of 5G millimeter wave applications has the completely same structural principles as but different sizes from that for covering the low frequency band of 5G millimeter wave applications. For example, for the two types of antennas, their corresponding stub tuners have different positions and lengths, and the corresponding shorter feed sections vertically arranged (i.e., their corresponding third and sixth feed sections) of their corresponding feed structures have different lengths, etc.
In one embodiment, a 1×4 ultra-wideband cross-polarized array antenna is formed by the above ultra-wideband cross-polarized antennas for covering the high frequency band of 5G millimeter wave applications, and
To sum up, the ultra-wideband cross-polarized antennas of one or more of the above embodiments have the following advantages over most popular patch array antennas: simple structure without the need for aperture coupling and parasitic elements; ultra-wide bandwidth with the capability of covering 5G millimeter wave full frequency band, i.e., the low frequency band of 24.25-29.5 GHz and the high frequency band of 37-52.6 GHz; good return loss in the working frequency band (better than −10 dB), good isolation between the two cross-polarized ports, high efficiency (better than 80% for all frequency bands), and a single cross-polarized antenna's wider HPBW (half-power beam width) than most patch antenna elements; the easiness to be integrated with the beamformer RFIC on the main PCB; and a wider beam scanning range of the array antenna constructed by the ultra-wideband cross-polarized antenna in the above embodiments than most patch array antennas.
What is described above is only the embodiments of the present invention, and is not intended to limit the patent scope of the present invention. Any equivalent variations made by using the contents of the specification and drawings of the present invention, which are directly or indirectly applied in related technical fields, are similarly included within the patent protection scope of the present invention.
The use of the terms “a”, “an” and “the” and similar referents in the context of describing the subject matter (particularly in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated therein, and each separate value is incorporated into the specification as if it were individually recited herein. Furthermore, the foregoing description is for the purpose of illustration only, and not for the purpose of limitation, as the scope of protection sought is defined by the claims as set forth hereinafter together with any equivalents thereof entitled to. The use of any or all examples, or exemplary languages (e.g., “such as”) provided herein, is intended merely to better illustrate the subject matter and does not pose a limitation on the scope of the subject matter unless otherwise claimed. The use of the term “based on” and other like phrases indicating a condition for bringing about a result, both in the claims and in the written description, is not intended to foreclose any other conditions are bright about that result. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention as claimed.
The embodiments described therein included the one or more modes known to the inventor for carrying out the claimed subject matter. Of course, variations of those embodiments will become apparent to those of ordinary skilled in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventor intends for the claimed subject matter to be practiced otherwise than as specifically described therein. Accordingly, this claimed subject matter includes all modifications and equivalents of the subject matter recited in the claims appended hereinto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed unless otherwise indicated therein or otherwise clearly contradicted by context.
| Number | Name | Date | Kind |
|---|---|---|---|
| 11177582 | Seo | Nov 2021 | B2 |
| 20170288312 | Koskiniemi | Oct 2017 | A1 |
| 20220077593 | Lee | Mar 2022 | A1 |
| 20230253719 | Bhattacharya | Aug 2023 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20240055776 A1 | Feb 2024 | US |
